October was the worst month since January for the slots parlor at Plainridge Park Casino, and MGM Springfield saw players wager less money — and therefore counted less in revenue — than they did during the casino’s first full month of operation, according to new revenue figures released Thursday by the Massachusetts Gaming Commission.

Players wagered $165.68 million on MGM Springfield’s slot machines last month and while 91.17 percent of it was returned to players as winnings, MGM Springfield reported $14.6 million in gross slot revenue last month. The casino also counted $7.6 million in gross revenue from its table games in October for total monthly revenue of $22.24 million. Revenue was down in all categories at the state’s first full-scale casino, which opened Aug. 23 and counted $26.95 million in monthly revenue in September.

Full-scale casinos in Massachusetts are taxed at a rate of 25 percent of their gross gaming revenue and the monthly state tax haul from MGM in October was $5.56 million, the Gaming Commission said. At the slots parlor in Plainville, officials reported slots revenue of $13.52 million last month from $170.44 million in wagers, the commission said.

Plainridge Park had only previously recorded less than $14 million in monthly revenue twice this year and October’s take was the lowest for a month since January, when the slots parlor took in $12.5 million. The state is entitled to more than $5.4 million of Plainridge’s October revenue in the form of state taxes intended for local aid and another $1.22 million for the Race Horse Development Fund. That works out to a total tax or assessment hit of about $6.6 million last month, according to the Gaming Commission.

Plainridge is taxed on 49 percent of its gross gaming revenue, with 82 percent of the levy going to local aid and 18 percent to a fund set up with the goal of supporting horse racing, an industry that is struggling in Massachusetts, according to SHNS.